Year : 2022 | Volume
: 22 | Issue : 1 | Page : 1--8
Collateral ligament injury of the knee in sports
Mohammad Abdullah Almalki1, Ibrahim Ahmed Altawayjri2, Mohammed Talal Alzahrani2, Ali Awash Aljizani1, Ali Mohammed Aseeri1, Abdullah Metab Alanazi1, Ahmed Khalaf Alanazi3, Nawaf Mohammad Alkhirat3,
1 Department of Reconstructive Orthopedic, King Fahad Medical City, Riyadh, Saudi Arabia
2 Department of Surgery, Orthopedic Division, King Abdulaziz Medical City, Riyadh, Saudi Arabia
3 Department of Orthopedic, King Saud Medical City, Riyadh, Saudi Arabia
Mohammed Talal Alzahrani
Department of surgery, Orthopedic Division, King Abdulaziz Medical City, P.O. Box 22490 Riyadh 11426
Athletes are particularly susceptible to medial or lateral collateral ligament injuries of the knee while playing sports. Sports are responsible for nearly half of all collateral ligament injuries, many of which are mild to moderate in severity. Frequently, the collateral ligaments are injured in association with other ligaments of the knee, necessitating surgical intervention and other measures to treat these injuries and restore full range of motion and function in the knee. In this review, we first discuss the stabilizing and supportive role of the collateral ligament and address why it is particularly susceptible to injuries in a sports setting. We then address the types of sports most frequently associated with damage to these ligaments, and note the role of gender and contact versus noncontact sports in the varying incidence rates of sports-related injuries observed in the literature. While conservative measures are typically used to treat collateral ligament injuries, more severe cases (particularly injuries that involve multiple ligaments) do require surgical intervention, with outcomes depending on the affected structures. We conclude by discussing a number of preventive strategies that can be employed to protect these ligaments – and the knee – from new or recurrent damage, with the hope that these preventive measures will be incorporated into future practice. Ultimately, athletes and clinicians should be informed on how to prevent debilitating injuries to preserve athletic performance and enhance or maintain an athlete's current quality of life.
|How to cite this article:|
Almalki MA, Altawayjri IA, Alzahrani MT, Aljizani AA, Aseeri AM, Alanazi AM, Alanazi AK, Alkhirat NM. Collateral ligament injury of the knee in sports.Saudi J Sports Med 2022;22:1-8
|How to cite this URL:|
Almalki MA, Altawayjri IA, Alzahrani MT, Aljizani AA, Aseeri AM, Alanazi AM, Alanazi AK, Alkhirat NM. Collateral ligament injury of the knee in sports. Saudi J Sports Med [serial online] 2022 [cited 2022 Jun 28 ];22:1-8
Available from: https://www.sjosm.org/text.asp?2022/22/1/1/342528
The knee is a complex yet resilient joint that is able to withstand great pressure and much strain. This hinge joint supports numerous anatomical functions and activity-based motions, such as rotation and flexion; it can absorb the shocks of jumping or falling, and it is highly involved in general ambulatory movements, such as walking, running, and balancing. The knee is comprised several musculoskeletal structures that both support and enable its diverse functions. The lateral collateral ligament (LCL), medial collateral ligament (MCL), anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), patellar tendon, meniscus, and articular cartilage offer the knee its flexibility. Helping it complete numerous types of rotations while guarding it against unnatural movements. These structures help restore the knee to its original anatomical position by stabilizing the knee following impact, injury, or distortion. Injury or strain to these stabilizers can result in a great burden or overcompensation of the other structures, leading to both physical and psychosocial consequences to the patient.
While the knee can endure much pressure, strain, and impact, there are instances when it is susceptible to debilitating or permanent injury, typically as a result of tendon or ligament rupture or tear. The collateral ligaments are particularly important in protecting the knee against injury because they work in tandem with the ACL to serve as a restraining force in abduction movements., The LCL stabilizes the knee during varus stress, while the MCL anchors the knee during valgus stress., These ligaments are most susceptible to various injuries, especially during smaller movements, but collateral ligament injuries may contribute to injuries of the larger ligaments, as the latter can overcompensate and bear unnecessary load to restabilize the joint in its compromised state., This is presumably why MCL injuries most frequently occur in tandem with ACL injuries,, especially during jumping motions,, while LCL injuries tend to be implicated alongside PCL injuries.,
As many as 50% of knee injuries are caused by playing sports; approximately 32%–40% of all knee injuries directly result from sports participation., In this setting, MCL injuries are generally much more common than LCL injuries;,,,, however, LCL injuries tend to be associated with higher pain and symptom scores, especially if they occur in conjunction with an ACL injury., Other works have noted that the ACL is the most frequently injured structure in the knee (it is affected in as many as 45.4% of all sports-related injuries), followed by the MCL in 17.6% of cases and the LCL in 2.5% of cases.
In this manuscript, we aim to discuss the role of the collateral ligament and the nature of its injuries. We then report the incidence of sports-related collateral ligament injuries in the general population while detailing how gender and specific sports are most frequently associated with these types of injuries. Next, we provide a review of the literature to address how collateral ligament injuries are diagnosed, managed, and treated, and we offer suggestions for injury prevention to inform current practice.
A PubMed literature search was performed with the following keywords: “collateral ligament” OR “medial collateral ligament” OR “lateral collateral ligament” AND “knee” AND “sports injury” OR “sports injuries” OR “sports-related injury” or “sports-related injuries”. Only those articles and/or abstracts published in English and those written and published until 2016 were included in this report. Moreover, additional pertinent manuscripts cited in the reference lists of these publications were also incorporated. Manuscripts pertaining to animal studies were not included; only full-text papers assessing or reviewing human subjects or human anatomy were cited herein. While the search yielded 53 relevant articles, the most relevant 44, and an additional book reference, were reviewed and included in this study.
The Collateral Ligament
It has been widely verified that the collateral ligament plays an important role in restraining the ACL during jumping or abducting motions, particularly during athletic activity. During gait, the MCL serves as a primary restraint, while the ACL serves as a secondary restraint to protect the joint from abduction. The ligaments play various roles during flexion; at smaller angles of 0°–30°, the PCL and MCL serve as the primary ligamentous restraints, that protect the knee during valgus stress and internal rotation. At larger degrees of flexion (60°–90°), the PCL and LCL then act as primary restraints, followed by the ACL and MCL at flexion angles of 90°–120°, while the largest degrees of flexion (120°–150°) primarily depend on the ACL to stabilize the joint. Given their greater involvement in stabilizing the joint during flexion, the ACL and MCL tend to be most at risk of injury during various activities, particularly in sports participation., In fact, the ACL bears most of the strain, weight, and force of larger athletic movements, including side stepping and jumping, and while bearing natural bodyweight and force; however, the MCL stabilizes smaller movements, so when the ACL is overloaded and subsequently injured, the MCL is frequently implicated and injured as well. Conversely, MCL damage can sometimes precede ACL injuries, as laxity in the MCL leads the ACL to overcompensate and bear most of the weight and strain of the joint, thus placing it at greater risk of also being injured.
Sports and Collateral Ligament Injuries
Overall, participation in sports represents one of the leading causes of injury to the knee; similarly, knee injuries are the most common lower extremity injuries to be found in athletes. In an early study by Hede et al., injuries such as ligament rupture, sprain, or tear most frequently occurred while playing football, skiing, playing team handball, practicing judo, cycling, or playing basketball, volleyball, baseball/softball, or soccer.,,,,, The motions that resulted in the greatest amount of injury to the knee included player-to-player contact, pivoting, jumping, and landing., In fact, contact with another person accounts for as many as 50.3% of knee injuries.,
Males under 30 years of age, especially those between 20 and 29 years old,,, are most at risk for developing knee injuries; this group accounts for nearly 68.1% of all cases of ligament damage, including knee sprains, ACL or medial meniscus tear, chondral lesions, MCL tears, trauma-related contusions, lateral meniscus tear, and patellar dislocation., Conversely, females' collateral ligament (and knee) injury rates tend to remain fairly stable between the ages of 10 and 39 years, which may be due to the different types of activities in which these two groups engage. Boys are more likely than girls to experience contact-related injuries when playing football, wresting, and ice hockey, while girls are more likely to experience noncontact-related knee traumas when playing volleyball, basketball, gymnastics, and lacrosse. Boys are more likely to experience noncontact-related collateral ligament injuries when playing basketball.
With respect to specific injuries, Swenson et al. reported that athletes were most likely to face ligament sprains (accounting for 48.2% of knee injuries), followed by contusions (14.9%) and injuries to the meniscus (9.3%). There were 6.29 per 10,000 injuries related to football (this sport was responsible for 62.0% of all knee injuries in boys alone, and for 43.9% of all knee injuries), 4.53 related to girls' soccer, and 4.23 related to girls' gymnastics. Low rates of knee injuries were reported for boys' swimming and diving, at a rate of 0.15 per 10,000 injuries. For “gender-comparable sports (soccer, volleyball, basketball, baseball/softball, lacrosse, swimming and diving, and track and field),” the researchers found that girls were more likely than boys to sustain injury, especially in soccer, basketball, baseball/softball, and track and field.
While all ligaments are susceptible to injury, sports that involve a great deal of impact to both the MCL and ACL tend to be associated with greater trauma to the collateral ligaments in general.,, In fact, of all sports-related knee dislocations, as many as 60% involved MCL tears, which were mostly found among amateur athletes. However, certain professional sports – particularly contact sports – are also associated with high rates of knee injuries. For instance, American football players present with some of the highest rates of MCL and ACL damage., Ice hockey players are also at great risk for MCL tears,, as 60% of all injuries to the knee involve trauma to this ligament.
In noncontact sports, participation in tennis and gymnastics is associated with greater injuries to the LCL; judo, skiing, and cross-country skiing typically result in injuries to the MCL;,,, participation in handball or volleyball results in injuries to the ACL; and handball is responsible for PCL injuries. In skiing, the specific load-bearing motions involved in shifting one's body weight from one knee to the other are particularly damaging to the MCL and ACL, especially when a skier falls forward and twists his or her body, leading to excessive loading during “external axial and valgus moments.”
Surprisingly, breaststroke swimmers are at great risk of collateral ligament damage and subsequent patellofemoral osteoarthritis development., These athletes experience tenderness in response to whip kick motions. While one may assume that repetitive strain associated with frequent kicking motions results in this trauma, Vizsolyi et al. noted that MCL injuries or pain among these athletes most frequently occurred in response to hip abduction movements upon kick initiation, and not to repetitive strain.
Impact of Collateral Ligament Injuries
Irrespective of the type or extent of injury, knee traumas are detrimental to athletes' performance and quality of life, particularly as ligament sprains, strains, tears, and ruptures can have long-lasting effects on an athlete's ability to engage in a full range of motion in the affected joint., Swenson et al. noted that knee injuries were involved in 15.2% of all sports injuries among student athletes in the United States. These injuries frequently require surgical treatment and result in lengthy absenteeism from school and sports participation. Students' academic and athletic performance ultimately suffers, and their families are also greatly affected by the expense of having to pay for surgical treatments. To safeguard against these negative experiences and consequences, researchers and clinicians are emphasizing the importance of timely and accurate diagnosis and treatment, and they are also recommending numerous preventive measures, each of which will be discussed in the following sections.
Diagnosis of Collateral Ligament Injuries
Clinical suspicion of collateral ligament injury starts with a history of trauma followed by knee pain or popping sound at the time of injury, clinical examination includes medial or lateral joint line tenderness, knee effusion, and ecchymosis. Stability examination by varus and valgus stress test may show joint laxity based on the extent of injury. Imaging is of critical importance when accurately diagnosing collateral ligament injuries. Konig noted that diagnosing collateral ligament injuries of the knee often involved diagnostic arthroscopy, where a tiny incision is made in the skin, and surgical instruments (including a small camera) illuminate and magnify the joint structures, enabling the surgeon to view any tears in or damage to the affected ligaments. This method provides a definitive diagnosis of knee injuries and trauma, but other less invasive measures are often used as first-line diagnostics.
For instance, magnetic resonance imaging (MRI) can be used to diagnose MCL injuries, which can be graded into three types. Grade 1 is a minor sprain (i.e., hyperintense signals are apparent medial to the ligament), Grade 2 injuries involve severe sprain or partial tears (i.e., partially disrupted hyperintense signals are found medial to the ligament), and Grade 3 injuries involve total ligament disruption.,, Lundberg et al. highlighted how sagittal T1- or T2-weighted images or coronal three-dimensional gradient images can be useful in diagnosing collateral ligament injuries. Of the 69 patients in their study, 77% had a sports-related injury. MRI was able to detect partial or total MCL tears with 56% sensitivity and 93% sensitivity; however, it was better able to detect ACL tears with 86% sensitivity and 92% specificity, which was also verified in another study. It was assumed that this reduced sensitivity and specificity associated with identifying MCL injuries were related to the amount of blood present at the site of injury, the rate of hemoglobin degradation, and the catabolic processes involved. The authors thus concluded that arthroscopy remained the gold standard for identifying knee injuries, and it was still the best method to determine which patients qualified for surgical interventions. A more recent work also confirmed that MRI is not the most suitable method for assessing the presence or extent of collateral ligament injury in patients, although it may constitute an important first step in noninvasive diagnostics.
Treating or Managing Collateral Ligament Injuries
Conventionally, mild-to-moderate knee injuries in sports have been treated or managed with conventional, conservative measures, including resting and/or elevating the joint, compressing the affected joint with a bandage, or placing ice on the affected joint to reduce swelling., The use of a cast to immobilize the knee can further promote healing of the affected joint and ligament when worn for at least 6 weeks.
Mild (Grade 2 and 3) MCL injuries are typically treated with the use of a brace. While many athletes wear knee braces or neoprene sleeves to protect the joint from injury, it has been noted that athletes tend to wear them following recurrent knee injury. Properly fitted braces should be able to provide the knee with enough restriction and flexibility to promote the natural motion of the knee; the hinges of this protective device should not be overly restrictive, as this may slow or impair the athlete's performance and lead to increased (and often unnecessary) injury (for instance, 6.5% of athletic students experience a new knee injury while wearing a brace)., Interestingly, athletes who wear braces for long periods of time do not tend to exhibit declines in athletic performance.
Although immobilization or restriction with a brace can lead to improved outcomes for mild-to-moderate collateral ligament injuries, this is often not enough to help an athlete fully recover his or her full range of motion following injury. After immobilization or restraint, or even following a surgical intervention, rehabilitation efforts should be undertaken to restore motion in the knee, particularly if the affected ligament is swollen or strained.,, Rehabilitation sessions held in a whirlpool or swimming pool were associated with increased restoration of flexion. As soon as 90° movements were restored following the application of a primary intervention, it was noted that resistance exercises were highly valuable for enhancing and restoring the knee's strength. When a rehabilitation regimen is implemented early on the following injury, it can restore function in the knee, so much so that the outcomes are equivalent to those of surgical or immobilization interventions, particularly when used for MCL sprains. In this vein, athletes are able to return to the activities they enjoy with minimal restrictions.
Surgical approaches for isolated ligaments
While nonsurgical interventions are typically used in the treatment of collateral ligament damage in the knee, in more severe cases (such as with ligament ruptures or tears), surgery is often warranted., With respect to isolated ligament injuries, superficial MCL injuries or MCL injuries with correspondent meniscus or cruciate ligament tears can be treated surgically if there is excessive laxity that impairs the person's daily function or athletic performance.,, In many instances, repair of this issue was associated with greater functional outcomes and subjective reports of enhanced quality of life. Of note, Swenson et al. discovered that girls were more likely to be treated with surgery following sports-related injuries to the knee. In many cases, athletes frequently decide to delay or avoid surgery, particularly in cases of meniscal or ACL injuries, as they wish to continue their sports participation. However, this approach is typically not recommended for many reasons. For instance, ice hockey players typically avoid undergoing surgical interventions to repair MCL injuries; as such, they have chronically unstable knees that compromise function and performance, rendering these players more susceptible to injury, even while wearing a knee brace.
Surgical interventions for collateral ligament tears in the knee are often most successful if performed in the acute stage of injury. In instances when MCL injuries require surgery following rupture, primary MCL repair is performed. Chiba et al. performed a suture and double-bundle reconstruction of the patellar tendon and MCL to repair an acute-stage rupture following a baseball slide. This approach protected the knee from developing chronic injury or scar tissue, thus enabling the patient to resume normal activities. The MCL can be repaired with at least four different types of techniques, including (1) anatomic single-bundle or (2) double-bundle repair, which restores the ligament's ability to protect against valgus stress and external rotations. Moreover, surgeons can (3) place a graft back in its anatomic position along the femur, and they can also (4) reconstruct the anatomic medial knee. Ultimately, it was concluded that proper graft placement can facilitate optimal outcomes for surgical cases of MCL injury. Patients with ruptures at the distal end of the joint line benefit most from surgical repair, as they are able to experience a greater return of flexion. Conversely, those with lesions or damage closer to or at the joint line fared worse in terms of their ability to regain full motion.
Although few studies have examined the procedures used to repair the LCL following sports-related knee injuries, an experimental, cadaveric study explored the use of grafts to reconstruct various components of the knee while also repairing this ligament. It was found that the LCL can be stabilized by inserting and fixating a hamstring graft into a longer femoral tunnel that is drilled at the point of anatomical insertion. This leads to reduced iatrogenic injury and restores greater stability to the LCL. Moreover, use of a cross-pin posterior to the LCL safeguards against tissue damage in the knee, while placing the pin directly across from or anterior to this ligament creates an undue risk of injury or damage to the joint. Preliminary treatment options using grafts that are fixated via sutures instead of intrabone tunnels have shown promise in medial patellofemoral ligament reconstruction, and this may have applications for future knee reconstruction following knee injury.
Surgical approaches for multiple ligaments
While surgical procedures are able to target an affected ligament in isolation, it should be noted that many collateral ligament injuries occur in tandem with other ligament or structural injuries. For example, simultaneous injuries to the ACL, MCL, PCL, and/or LCL are typical in sports contexts. ACL injuries are most likely to occur in tandem with medial meniscus (32.7%), MCL (24.6%), lateral meniscus (15.1%), PCL (1.2%), and LCL (1.8%) trauma. Therefore, individuals with dual ligament damage must undergo more aggressive treatment to help restore motion as quickly as possible.
Mamatkerimulla et al. reported that even multiple injuries to the knee can be effectively treated during their acute stages (i.e., from ~2 to 3 weeks), resulting in near or full recovery. Of the 22 cases examined, all had ACL and PCL rupture, while 11 cases had concurrent LCL rupture, 7 had meniscus injury, 2 had MCL and LCL rupture, and 2 had condylar avulsion fracture. All patients underwent one-stage reconstruction and knee immobilization for a total of 6 weeks. The patients generally exhibited significant improvements in the knee's range of motion, and patients recorded negative scores on the anterior and posterior drawer tests, valgus and varus stress tests, and Lachman test. As such, this method was lauded as safe and effective in treating knee traumas of various types.
As the ACL and MCL are often affected at the same time (typically with the ACL as the primary injury and MCL as the secondary trauma), it was found that ligament reconstruction using a fresh-frozen patellar tendon or Achilles allografts was able to restore motion (with a mean loss of movement of 5°) in most patients following knee dislocations; however, some movement restrictions were still evident postoperatively. Further, Sun et al. attempted surgical repair via mini incisions and using internal fixation with an absorbable screw to repair ACL injuries and, in 5 cases, a concomitant MCL injury. This method, in combination with postoperative rehabilitation exercises, yielded significantly improved scores on a number of function tests, including range of motion, Tegner, Lysholm, and International Knee Documentation Committee scores at 6–12-month follow-up. The authors thus concluded that this method was effective for repairing ACL tibial eminence avulsion fractures.
One case report by Chiba et al. highlights how a surgical intervention can effectively treat concurrent ligament injuries. A patient with simultaneous rupture of the patellar tendon, ACL, and MCL following a baseball slide underwent a surgical intervention to repair this injury. The authors were able to repair the knee by first suturing the patellar tendon and MCL in the acute phase of injury; then, 7 months postoperatively when healing began, the researchers performed a double-bundle reconstruction of the ACL, which successfully restored motion to the patient's knee with only a fiber wire thread.
A combined surgical/rehabilitative approach may also be highly effective for knee injuries involving the collateral ligaments and other structures. In their study, Chen et al. noted that irrespective of the type of knee injury or trauma involved, use of a surgical intervention, followed by joint fixation and rest for 3–4 weeks, functional exercises of the knee joint, and knee reconstruction via arthroscopy resulted in improved outcomes in their patients with multiple ligament injuries. Based on their results, the authors stated that valgus stress test scores, varus stress scores, and Lachman test scores improved. Within 12 months of surgery, the patients demonstrated an improved range of motion and excellent postoperative outcomes.
As a cautionary note, it is imperative to keep in mind that the surgical management of collateral ligament injuries highly depends on the nature and extent of the injury, as well as on the patient's anatomical variations in ligament placement. For instance, with respect to the LCL, it appears that the patellar tendon can insert posterior to and run alongside the LCL at the long axis of the femur, but it can also be inserted on the anterior side of the popliteal sulcus (as occurs in most cases). However, there are many instances where the LCL also inserts at the posteriodistal point of the lateral epicondyle's apex. This affects graft positioning and the choice of surgical intervention. For a comprehensive review, Woo et al. provide an in-depth discussion of the use of functional tissue engineering in ligament and tendon repair.
In addition, flexion angle and ligament length also impact which procedure is used for specific types of injury. As briefly described earlier in this report, Ozada addressed how different ligaments are implicated in various degrees of flexion and how different ligament lengths afford the knee its flexibility during certain movements. In this context, surgeons must keep in mind that anatomical variations in ligament length and flexibility ultimately affect which surgical procedure is chosen, as each choice may largely depend on the desired functional outcomes.
Collateral Injury Prevention
Since athletes are particularly susceptible to collateral ligament injuries of the knee while participating in sports, it has long been recommended that athletes engage in stretching and warm-up activities, such as walking or light jogging, to limber up the muscles and ligaments to stave off potential motion-based injuries.,
Another approach to preventing ligament injuries is to modify specific or repetitive motions in such a way that accommodates the natural motion of the typically affected ligament. Among breaststroke swimmers, for instance, it was argued that modifications to the initial kick motion would reduce the strain experienced by both novice and experienced swimmers, thus reducing medial knee strain.
Devices can also be used to protect the collateral – and other – ligaments from injury. Importantly, the use of prophylactic knee braces is an effective method to prevent subsequent MCL injury. Knee braces are able to protect against lateral impact by 20%–30%; however, it seems that the ACL benefits more from this type of protection than does the MCL. Moreover, among ice hockey players, the use of protective equipment, ample training, and muscle conditioning was associated with reduced injuries or tears to the MCL. Among 600 Swedish ice hockey players, Tegner and Lorentzon found that 23% chose to wear a at least one knee derotation brace; 88% of players who wore a brace had reported experiencing a prior knee injury. Of those who wore the brace, 17 experienced a new injury, which frequently involved the MCL, although one involved an ACL tear. While there were high rates of MCL and ACL injuries overall (even among brace wearers), use of a prophylactic knee brace did mitigate the occurrence of a new knee injury, justifying the need to use protective equipment in ice hockey. Furthermore, in skiing, Hull argues that the ability to release a toe piece when twisting is critical for protecting a skier from injuries to the MCL given the external axial rotations involved. It was also reinforced that poorly adjusted or poorly designed bindings result in greater number of injuries in Alpine skiers, as these bindings do not properly support the joint during the various motions associated with this sport.
Taken further, some researchers have even investigated whether altering playing surfaces can help mitigate the risk of developing collateral ligament injuries. As American football players experience some of the highest rates of MCL injury,, Powell and Schootman investigated the incidence of injuries experienced by NFL players on AstroTurf surfaces. The authors discovered that this surface was associated with high number of ACL sprains and other injuries. In addition, when playing on AstroTurf, certain types of players (e.g., linemen) were more likely to face MCL injuries than other players (e.g., backs, who were more likely to experience ACL injuries during rushing or passing plays). To address this, Hershman et al. examined whether using a softer FieldTurf would prevent these injuries in NFL players. It was discovered that altering the playing surface did not, in fact, prevent injuries to this ligament during American football. Altering the field surface actually increased the rate of ACL and ankle sprains, highlighting the importance of conducting further investigations to better assess which factors and measures can best protect athletes from specific types of trauma.
Athletes are highly prone to collateral ligament injuries of the knee. In this review, we examined the types of collateral ligament and knee injuries that can arise while playing specific sports. We then highlighted various diagnostic, treatment, and preventive measures that can be employed to improve the prognosis of various athletes. While the nature and etiology of collateral ligament injuries of the knee are highly diverse, effective preventive measures and treatment in acute stages are particularly important for facilitating an athlete's ability to participate in his or her sport of choice, while also maximizing outcomes and enhancing quality of life. Future research should delve into uncovering which preventive measures and treatments are best able to help athletes who are prone to experiencing single versus multiple ligament injuries in the knee. Moreover, additional efforts must be made to design effective prophylactic knee braces to both protect the knee and preserve its natural flexibility and movement.
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